Schema mark up Discussion

Schema markup is showing the details of a firm as per their choice, i.e. when you type "Cab Seruve" in Google, it gives the top most websites in the Google Maps, by showing its name, phone number, address, also it shows rating. It is the choice of the firm to display like this to the customers. That we call it as schema markup. If any one knows more than this tell me. It is very important in SEO.